Norwich City Council has given fresh backing to the principle of the Western Link, which would connect the Northern Distributor Road to the A47 - despite claims by critics it will be 'a folly'.

The opposition Green group at City Hall tabled a motion urging the authority to reverse the Labour-controlled cabinet's recent decision to support the principle of Norfolk County Council's vaunted road.

But, despite support from the Liberal Democrats, the motion was defeated.

Green group leader Denise Carlo's said the road would cause environmental harm and would cost more than the estimates the county council used during consultation.

Ms Carlo said: 'All Western Link routes would cause irreversible environmental harm to the Wensum and Tud valleys, promote major traffic-generating development in a rural area, increase greenhouse gas emissions, and suck up public money.'

As members of campaign group Extinction Rebellion held up a Protect The Wensum Valley banner, she said money would be better pumped into sustainable transport.

The county council recently carried out consultation over four options, ranging in cost from £61m to £161m.

Some of the options would require a viaduct to be built over the Wensum Valley and a bridge over the Tud Valley.

The Norfolk Wildlife Trust has raised concerns that, without a 'significant commitment' to mitigation, the road could cause 'unacceptable' damage to habitats for animals, plants and birds.

The county council has said it is committed to minimising potential adverse impacts of the road and has been seeking advice from Natural England and the Environment Agency.

Labour's Mike Stonard, cabinet member for sustainable and inclusive development, said, while the cabinet had given support in principle, a final decision had yet to be made.

He said the council needed to balance the city's economic needs and mitigating the environmental impacts.

He said the council would only support the road if it came with sustainable transport measures for Norwich.

And Labour's Roger Ryan said: 'I look forward to seeing the missing link built and electric vehicles travelling along the road.'

But Green councillor Ben Price said: 'This road will become a folly and it's disappointing to hear you support it. Supporting this road shows how this administration is trapped in the last century.'

On Ms Carlo's claims about the road's costs, a county council spokeswoman said: 'The estimated costs for each of the route options that we consulted on are based on realistic valuations and the experience and knowledge of professional people with specific expertise in their respective fields.'